Pull request: all: add native endianness, imp Makefile

Merge in DNS/adguard-home from fix-some to master

Squashed commit of the following:

commit 190e9a88d9c0f2bfc597aa61b41dae8b8686158e
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Mar 16 20:50:02 2021 +0300

    all: add native endianness, imp Makefile

internal/aghos/endian_big.go

@@ -0,0 +1,10 @@
+// +build mips mips64
+
+// This file is an adapted version of github.com/josharian/native.
+
+package aghos
+
+import "encoding/binary"
+
+// NativeEndian is the native endianness of this system.
+var NativeEndian = binary.BigEndian

internal/aghos/endian_little.go

@@ -0,0 +1,10 @@
+// +build amd64 386 arm arm64 mipsle mips64le ppc64le
+
+// This file is an adapted version of github.com/josharian/native.
+
+package aghos
+
+import "encoding/binary"
+
+// NativeEndian is the native endianness of this system.
+var NativeEndian = binary.LittleEndian

internal/home/authglinet.go

@@ -8,9 +8,9 @@ import (
 	"net/http"
 	"os"
 	"time"
-	"unsafe"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghio"
+	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
 	"github.com/AdguardTeam/golibs/log"
 )
 
@@ -66,16 +66,6 @@ func glCheckToken(sess string) bool {
 	return now <= (tokenDate + glTokenTimeoutSeconds)
 }
 
-// TODO(a.garipov): Replace with a smaller version of
-// https://github.com/josharian/native.
-func archIsLittleEndian() bool {
-	var i int32 = 0x01020304
-	u := unsafe.Pointer(&i)
-	pb := (*byte)(u)
-	b := *pb
-	return (b == 0x04)
-}
-
 // MaxFileSize is a maximum file length in bytes.
 const MaxFileSize = 1024 * 1024
 
@@ -104,12 +94,7 @@ func glGetTokenDate(file string) uint32 {
 	}
 	buf := bytes.NewBuffer(bs)
 
-	var order binary.ByteOrder = binary.BigEndian
-	if archIsLittleEndian() {
-		order = binary.LittleEndian
-	}
-
-	err = binary.Read(buf, order, &dateToken)
+	err = binary.Read(buf, aghos.NativeEndian, &dateToken)
 	if err != nil {
 		log.Error("binary.Read: %s", err)
 

internal/home/authglinet_test.go

@@ -1,12 +1,12 @@
 package home
 
 import (
-	"encoding/binary"
 	"io/ioutil"
 	"net/http"
 	"testing"
 	"time"
 
+	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -20,19 +20,14 @@ func TestAuthGL(t *testing.T) {
 	})
 	glFilePrefix = dir + "/gl_token_"
 
-	putFunc := binary.BigEndian.PutUint32
-	if archIsLittleEndian() {
-		putFunc = binary.LittleEndian.PutUint32
-	}
-
 	data := make([]byte, 4)
-	putFunc(data, 1)
+	aghos.NativeEndian.PutUint32(data, 1)
 
 	require.Nil(t, ioutil.WriteFile(glFilePrefix+"test", data, 0o644))
 	assert.False(t, glCheckToken("test"))
 
 	data = make([]byte, 4)
-	putFunc(data, uint32(time.Now().UTC().Unix()+60))
+	aghos.NativeEndian.PutUint32(data, uint32(time.Now().UTC().Unix()+60))
 
 	require.Nil(t, ioutil.WriteFile(glFilePrefix+"test", data, 0o644))
 	r, _ := http.NewRequest(http.MethodGet, "http://localhost/", nil)